#!/bin/bash  
# Create global variables   
# Define Bridge Interface 
br="br0" 
# Define list of TAP interfaces to be bridged, 
# for example tap="tap0 tap1 tap2". 
tap="tap0" 
# Define physical ethernet interface to be bridged 
# with TAP interface(s) above. 
eth="eth0" 
eth_ip="10.1.0.4" 
eth_netmask="255.255.255.0" 
eth_broadcast="10.1.0.255" 
gw="10.1.0.1"   
start_bridge () {   
#################################   
# Set up Ethernet bridge on Linux   
# Requires: bridge-utils   
#################################    
for t in $tap; do
openvpn --mktun --dev $t   
done    
for t in $tap; do
ifconfig $t 0.0.0.0 promisc up   
done
ifconfig $eth 0.0.0.0 promisc up
brctl addbr $br 
brctl addif $br $eth
for t in $tap; do
brctl addif $br $t   
done    
ifconfig $br $eth_ip netmask $eth_netmask broadcast $eth_broadcast up   
route add default gw $gw $br
} 
stop_bridge () {   
####################################   
# Tear Down Ethernet bridge on Linux   
####################################    
ifconfig $br down
brctl delbr $br    
for t in $tap; do
openvpn --rmtun --dev $t   
done   
ifconfig $eth $eth_ip netmask $eth_netmask broadcast $eth_broadcast up   
route add default gw $gw $eth
}  
case "$1" in 
start)   
echo -n "Starting Bridge"   
start_bridge   
;; 
stop)   
echo -n "Stopping Bridge"   
stop_bridge   
;; 
restart)   
stop_bridge   
sleep 2   
start_bridge   
;; 
*)   
echo "Usage: $0 {start|stop|restart}" >&2   
exit 1   
;; 
esac